BY T. H. JOHNSTON AND M. J. BANCROFT. 197 
vein is almost straight. The discal nervure is distinctly 
curved with the concavity facing towards the base of the 
wing. The alula is rather more rhomboidal than that 
of M. domestica. The squame is very pale or whitish. 
Halteres are long and yellowish. The legs are black. 
Abdomen. The first segment is black with coloura- 
tion extending backwardly as in fig. 5, forming a fairly 
broad median stripe with lateral extensions in the hinder 
portion of each segment, these varying in different 
individuals. The greater part of the dorsum of the 
abdomen is of a pale golden hue which stands out in sharp 
contrast with the black median band. The abdomen is. 
densely setose. Ventrally it is yellowish with black coloura- 
tion in the region of the genital aperture. 
Female. 
The general appearance of the female is markedly 
different from that of the male, chiefly on account of the 
tessellated appearance of the abdomen dorsally, while 
ventrally it has a more or less uniform smoky-grey colour. 
The thoracic region is distinctly greyer. The fly then 
appears to have a rather lighter coloured thorax and a 
darker abdomen than the male. The main points of differ- 
ence are as follows: Eyes widely separated by a distance 
approximating a-third of the width of the head; a broad 
frontal stripe about half the width of the area between 
the eyes : the frontal margins extending upwards on either 
side of the frontal stripe downwards as a very distinct 
silvery band on either side of the antenne. 
Thorax. The thoracic markings are arranged much 
the same as in the male, similar variations also being met 
with (fig. 2). 
Abdomen. The markings on the dorsal surface of 
the abdomen are characteristic—their arrangement being 
indicated in fig 2. The first segment is black On 
succeeding segments there is a median dorsal stripe resemb- 
ling that of the male, but there is laterally on each segment 
a dark band extending somewhat obliquely from the anterior 
to the posterior margin of each segment. The pigment 
patch on the first segment commonly invades the anterior 
portion of the succeeding segment. 
